If the headspace is ok in the original barrel (if you have shot out the throat we'd have to assume it is) you can send the old barrel in to a good gunsmith and have it copied, right down to the depth of the chamber, so the headspace would be exactly the same.
The contour would be very close (it's best to make the new one about .010" oversize so you can use a dowel and sandpaper only to "inlet” it perfectly, or go larger if you’d like)
All you’d have to do is screw it in.
I have done this kind of work many times for customers in other states who don’t want to mess with shipping to an FFL and jumping through the hoops. A barrel is not regulated by state of federal law.
If the old barrel has sights on it you’d need to sweat them on the new barrel when it gets back to you and after it’s screwed into the action. Then you need only clean up the solder and blue it .
If the barrel is stainless you need not blue it at all
On a Mauser you can expect to pay about $150 for the work plus the price of the barrel.
That would be for threading, chambering/headspacing, contouring crowning and polishing. Add that to the price of the new barrel of your choice, plus shipping both ways and you have an approximate total